• “Faces of America with Henry Louis Gates” (7 p.m., PBS, check local listings) enters its second week, with the host taking his celebrity participants back to the 19th century to trace the their ancestors’ first years in the New World.

Comedian and fake pundit Stephen Colbert’s great-great-grandfather was the first of his family to leave Limerick, Ireland. Mario Batali’s great-grandfather wandered far from Italy to work in Montana’s quartz mines.

While 19th-century immigrants from Europe faced hardships and discrimination, Kristi Yamaguchi’s ancestors and all Asian immigrants of the period were subject to race-specific laws and federal legislation barring their entry and citizenship.

• Facing Olympic competition, ABC airs two repeats of “Modern Family” and allows viewers to see why this documentary-style ensemble series has been so quickly embraced by critics and audiences alike.

In the first (7 p.m.), Mitchell plays head games with his gruff father, Jay, insinuating that his regular-guy pal (Chazz Palminteri) may not be all man. In the follow-up (8 p.m.), Jay’s enthusiasm for his stepson Manny’s fencing prowess forces Mitchell to recall his father’s indifference to his childhood ice-skating dreams.

In a show in which the entire cast is excellent, Ed O’Neill stands out. Having made his name as the cheerfully vulgar patriarch of the Bundy family on “Married ... with Children,” O’Neill has made the most of a more complex character. Slightly exhausted and hopefully wiser for his years, Jay is the first to admit that he hardly deserves his voluptuous trophy wife and the second chance he has been given as a father. Not unlike Archie Bunker in the later seasons of “All in the Family,” he seems willing to admit shortcomings and to embrace change. Just as long as it doesn’t come too quickly, or with too many hugs.